Various types and amounts of chemicals are added to a pulp mill process. In particular, chemicals are added into a process stream of a pulp mill process. The optimal feeding of these chemicals is both a quality and a cost issue in that the optimal feeding of chemicals into a process stream results in the following: a) better runnability of the paper machine; b) the quality of the end product is more predictable and uniform; c) less web breaks and down-time of the paper machine; d) a reduction in the quantity of the chemical that needs to feed into a papermaking machine; e) smaller consumption of fresh water; and f) less energy is needed to heat fresh water.
Optimal feeding of chemicals into a process stream occurs when there is rapid mixing of chemical into the process stream, presence of locally stoichiometric conditions, minimized water usage in the feeding arrangement, and optimal residence/contact times of chemicals. More specifically, having locally stoichiometric conditions means having the optimal ratio of chemicals in the process stream for the chemicals to react, and optimal residence time of the chemicals means that the chemicals should be fed into the process stream so that all the chemicals that have been fed into the system have had enough time to take effect but not too long to maintain the desired effect.
Many prior art methods for feeding chemicals into a pulp process stream of a pulp mill process do not result in the optimal feeding of chemicals into the pulp process stream. Therefore, a need for an apparatus and method that can optimally feed one or more chemicals into a pulp process stream exists in the papermaking industry.